From: Johan De Meersman
Date: March 11 2010 3:42pm
Subject: Re: Very slow delete for Master / Child tables with millions of rows
List-Archive: http://lists.mysql.com/mysql/220916
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If you really have to loop through the entire set deleting record by record,
I'm not surprised it's slow. Could you change your application to loop
through the records doing "stuff" without deleting (maybe even "do stuff" en
masse), and afterwards do a mass delete ?
I also have a nagging suspicion (unfounded by any actual experience, though)
that it might be faster to cut the explicit relations and do the child
deletes as a separate single-block execute, too. Easy enough to test, I
suppose.
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